1. Field of the Invention
The present invention relates to a data management apparatus and a data distribution system, and more particularly to a data management apparatus and a data distribution system for displaying ghost data based on a history of a game having been previously played.
2. Description of the Background Art
In a racing game system disclosed in Japanese Laid-Open Patent Publication No. 2003-320164, three-dimensional image data (ghost data) generated in a game which is played using an individual racing game apparatus is uploaded to a database server through a communication line so as to be stored in a high-capacity storage device of the database server. When a player of a racing game apparatus desires that a racing car of the player compete with a racing car (ghost car) which was previously operated by another player, the racing game apparatus accesses the database server through the communication line so as to download ghost data of the game selected from among ghost data which are obtained when other players previously played the game, and which are stored in the high-capacity storage device of the database server. At this time, based on a ranking list created by a management device of the database server, the ghost data ranked immediately above or a few ranks higher than data of the best record of the player operating the racing game apparatus is automatically selected. Thus, the player is allowed to cause his/her car to compete with a ghost car of another player who matches the player in skill.
However, the racing game system disclosed in Japanese Laid-Open Patent Publication No. 2003-320164 has a problem that a high-capacity storage device is necessary for storing all the ghost data uploaded to the database server from the individual racing game apparatuses. Further, the storage capacity of the high-capacity storage device is limited, and therefore the amount of the ghost data to be uploaded to the database server is also limited. Furthermore, the ranking list is created based on all the ghost data uploaded from the individual racing game apparatuses to the database server, and therefore there is a problem that processing load necessary for creating the ranking list is large.
In order to solve the problem, only the ghost data (for example, the ghost data for top 1000 players) ranked higher than a predetermined rank in the ranking list may be stored in the high-capacity storage device instead of storing, in the high-capacity storage device, all the ghost data uploaded from the individual racing game apparatuses to the database server. In this case, however, an unskilled player is not allowed to compete, in operating a car, with another player who matches the unskilled player in skill since the ghost data of the another player may not be stored in the high-capacity storage device of the database server.